38 Thomas Henry Huxley 



was no well-known form to serve as a standard of com- 

 parison for all the others in the fashion that the body 

 of man served as a standard of comparison for all 

 vertebrates. Here and there, a few salient tj^pes such 

 as insects and snails had been picked out, but know- 

 ledge of them helped but little with a great many of the 

 invertebrates. The great Linnaeus had divided the 

 animal kingdom into four groups of vertebrates : mam- 

 mals, birds, reptiles, and fishes, but for the invertebrates 

 he had done no more than to pick out the insects as 

 one group and to call everything else " Vermes" or 

 worms. The insects included all creatures possessed of 

 an external skeleton or hard skin divided into jointed 

 segments, and included forms so different as insects, 

 spiders, crabs, and lobsters. But Vermes included all 

 the members of the animal kingdom that were neither 

 vertebrates nor insects. Cuvier advanced a little. He 

 got rid of the comprehensive title Vermes — the label 

 of the rubbish-heap of zoologists. He divided animals 

 into four great subkingdoms : Vertebrates, Mollusca, 

 Articulata, Radiata. These names, however, only 

 covered very superficial resemblances among the ani- 

 mals designated by them. The word Mollusca only 

 meant that the creatures grouped together had soft 

 t)odies, unsupported by internal or external articulated 

 skeletons ; and this character, or, rather, absence of 

 character, was applied alike to many totally dissimilar 

 creatures. The term Articulata included not only 

 Linnaeus's insects but a number of soft-skinned, ap- 

 parently jointed, worm-like animals such as the leech 

 and earthworm. Lastly, tlie name Radiata meant no 

 more than that the organs of the creatures so desig- 

 nated were more or less disposed around a centre, as the 

 sepals and petals of a flower are grouped around the 



